Cancers of the cervix and endometrium affect 48,000 women per year. In spite of major advances in diagnostic x-ray surgery and radiation therapy, local control of these malignancies continues to be a problem. In 1985, there were 7,400 deaths from cancer of the cervix and 3,200 deaths from cancer of the endometrium. As part of the standard treatment for the more advanced cases, high-does intra-cavitary irradiation is delivered with a tandem and colpostat. This device can be secured in position in the endometrial canal and surrounding the cervix so that local, intense irradiation can be delivered. Still, locale failures continue to plague patients with more advanced local disease. The intent of this application is to obtain support for the development of modifications to current intracavitary applicators used in the treatment of gynecologic malignancies. This will make possible the delivery of intracacitary hyperthermia through the same devices that are used to deliver intracavitary irradiation. Hyperthermia is an emerging technology that allows complementary cytotoxicity to radiation. We propose to modify these applicators in such a way that local hyperthermia can also be delivered in an attempt to achieve better local control. Microwave and ultrasound heating devices will be incorporated to accommodate a wide variety of clinical situations. In particular, the tandem will be modified to accept an air- cooled microwave antenna. The colpostats (ovids) will be modified to include ultrasound transducers or microwave spiral applicators.